The Erathna Mini Hydropower Project is located in the Kuruwita Divisional Secretariat in the District of Ratnapura. The plant is ‘Run-of-the-River’ and utilizes the water flow of the upper reaches of the Kuru Ganga, which originates at the Adam’s Peak at an elevation of 2,100 meters above the mean sea level. The river leaves the boundary of the sanctuary at an elevation of 1,030 meters and continues onward as a tributary of the Kalu Ganga. The hydro plant infrastructure is sited on a total land extent of approximately 4.0 Ha, spanning two villages - Pelendakanda and Adavikanda. The land extent covers the land trace from the Weir through the Headrace channel up to the Forebay tank, the Penstock path, the Powerhouse and the Tailrace. The Powerhouse is located on the right bank of the river at Adavikanda and easily accessible by road. The water catchments area for the plant is estimated to be 14.5 square kilometres in extent. The water diversion point and the Weir are at an elevation of 840 meters above the mean sea level. The diverted water flows through the intake and along a covered Headrace channel to the Forebay tank.

It is then channelled down through a penstock of 2.4 kilo meters long to the Powerhouse, which is at an elevation of 377 meters. This provides a total energy head of 463 meters. Before reaching the Powerhouse, the Penstock bifurcates into two pipelines that feed twin Pelton turbines. The turbines drive the synchronous electric generators. The expended water is then released along the Tailrace channel to the Kuru Ganga.

The generated power is fed through two primary transformers and transmitted via an 18 km long interconnection line connecting to the Kosgama – Ratnapura 33 kV power line. The plant consists of turbine machinery manufactured by Voith Siemens, a reputed German producer of turbine machinery. The entire plant is operated, regulated and monitored from water intake to power generation by means of a computerized control system.

Monthly Power Generation

2010

2011

2012

2013

2014

2015

2016

2017

2018

Units
kWh

Units
kWh

Units
kWh

UnitskWh

UnitskWh

UnitskWh

UnitskWh

UnitskWh

UnitskWh

January

962,454

2,116,386

547,367

1,337,701

1,295,000

1,315,781

1,318,647

651,507

700,881

February

801,984

1,702,117

603,883

1,170,096

603,663

1,633,422

509,117

360,468

859,584

March

742,945

1,767,098

594,229

1,604,287

1,188,840

1,063,026

709,720

1,082,097

1,446,991

April

2,223,339

3,204,934

4,133,819

2,060,601

1,485,012

3,233,260

1,320,043

1,685,293

2,573,657

May

5,448,931

4,551,339

2,300,033

6,133,238

2,954,389

4,556,864

5,713,867

4,164,133

5,143,281

June

6,091,350

5,154,091

4,022,233

6,996,320

6,057,312

5,002,834

5,513,819

5,941,390

6,714,463

July

5,648,764

4,301,210

4,489,680

6,590,531

5,204,665

5,217,084

4,008,243

4,082,126

5,378,384

August

4,439,212

5,155,713

4,381,056

4,372,854

6,332,665

4,708,884

4,731,918

6,493,852

5,708,560

September

4,642,867

4,860,252

4,700,705

4,942,559

5,166,610

5,914,167

3,667,695

5,695,122

2,625,992

October

4,540,150

3,348,808

4,683,185

4,529,847

5,643,707

5,824,991

3,634,485

6,745,822

5,921,418

November

4,822,453

3,037,618

4,384,431

3,195,240

3,235,940

4,384,063

3,806,554

3,268,413

December

4,219,154

1,611,353

2,225,780

1,937,480

3,435,607

2,760,978

947,011

3,111,425

Total

44,583,603

40,810,919

37,066,401

44,870,754

42,603,410

45,615,354

35,881,119

43,281,648

37,073,211

Project Highlights

The Erathna Mini Hydropower Project is located in the Kuruwita Divisional Secretariat in the District of Ratnapura. The plant is ‘Run-of-the-River’ and utilizes the water flow of the upper reaches of the Kuru Ganga, which originates at the Adam’s Peak at an elevation of 2,100 meters above the mean sea level. The river leaves the boundary of the sanctuary at an elevation of 1,030 meters and continues onward as a tributary of the Kalu Ganga. The hydro plant infrastructure is sited on a total land extent of approximately 4.0 Ha, spanning two villages - Pelendakanda and Adavikanda. The land extent covers the land trace from the Weir through the Headrace channel up to the Forebay tank, the Penstock path, the Powerhouse and the Tailrace. The Powerhouse is located on the right bank of the river at Adavikanda and easily accessible by road. The water catchments area for the plant is estimated to be 14.5 square kilometres in extent. The water diversion point and the Weir are at an elevation of 840 meters above the mean sea level. The diverted water flows through the intake and along a covered Headrace channel to the Forebay tank.

It is then channelled down through a penstock of 2.4 kilo meters long to the Powerhouse, which is at an elevation of 377 meters. This provides a total energy head of 463 meters. Before reaching the Powerhouse, the Penstock bifurcates into two pipelines that feed twin Pelton turbines. The turbines drive the synchronous electric generators. The expended water is then released along the Tailrace channel to the Kuru Ganga.

The generated power is fed through two primary transformers and transmitted via an 18 km long interconnection line connecting to the Kosgama – Ratnapura 33 kV power line. The plant consists of turbine machinery manufactured by Voith Siemens, a reputed German producer of turbine machinery. The entire plant is operated, regulated and monitored from water intake to power generation by means of a computerized control system.